The present invention relates to weakly coordinating anion salts comprising a reactive cation and uses thereof. In particular, the present invention relates to fluoroborate salts comprising a reactive cation. Specifically, the present invention provides compounds of the formula MxQy, where M, Q, x, and y are those defined herein.
Weakly coordinating anion salts comprising a reactive cation are useful in variety of reactions including polymerization reactions, coupling reactions, and other chemical reactions which is facilitated by an appropriate cation. Useful reactive cations include silver cation, silylium cations, aluminum cations, ammonium cations, protonated arenes, triaryl carbocation, and other cations which can facilitate a chemical reaction such as a polymerization reaction, coupling reaction, and other catalytic reactions.
Currently, there are no methods to generate stable reactive cations, such as cation-like aluminum (i.e., pseudo aluminum-cation) species, e.g., AlMe2+1, in the presence of weakly coordinating anions (WCA""s). For example, when the AlMe2+1 was generated in situ, it caused the rapid decomposition of one of the most efficient WCA""s known, viz. B(C6F5)4xe2x88x921 (Al(C6F5)3 was one of the reaction products).1 Other cationic aluminum complexes are based on the use of bulky nitrogen ligands to stabilize the positive charge on the aluminum atom. The synthesis and characterization of aluminum alkyl complexes containing guanidimates, 2 amidinates, 3 aminotroponimates, 4 and pyridyliminoamide5 ligands have recently been reported. These complexes exhibited ethylene polymerization activity of 900-2,600 g PE/(molxc2x7atmxc2x7h) in toluene at 80 to 100xc2x0 C. and 1 to 5 atm of ethylene.1,4 However, the steric or electronic properties of the nitrogen ligands may disfavor the coordination and activation of large organic molecules. The synthesis of xcfx80-stabilized (xcex75-Cp*)2Al+1 has also been reported.6 
In addition, it is believed no examples of Cxe2x80x94H activation by cationic aluminum complexes has been reported. However, xcex71-arene complex of Al(C6F5)3 has recently been reported7, which may represent a model for the first step in Cxe2x80x94H activation of aromatic molecules by aluminum cationic complexes. The catalytic activation of aromatic Cxe2x80x94H bonds resulting in arene-olefin coupling is of considerable current interest for chemical and pharmaceutical industries.8, 9 Efficient palladium-catalyzed oxidative coupling of arenes with olefins has recently been reported.8 Other methods of arene-olefin coupling include use of strong Lewis acids (e.g., AlCl3) and Bronsted acids (e.g., HF, BF3.HF, and AlCl3.HCl).10 However these methods are usually accompanied by isomerization, disproportionation, and transalkylation. In addition, the use of WCA""s other than fluorocarborate anions such as 1-Rxe2x80x94CB11F11xe2x88x921 to generate AlMe2+1 cation-like species has resulted in rapid decomposition of the aluminum cation as well as the WCA. Furthermore, it is believed that no other stable aluminum compound can catalyze Cxe2x80x94H activation in the absence of a strong Bronsted acid.
Furthermore, many conventional co-catalysts for an xcex1-olefin (e.g., ethylene) polymerization, including methylalurnoxane (MAO), have limited solubilities in aliphatic hydrocarbon solvents and are not stable when stored in solution.11 
Therefore, there is a need for stable weakly coordinating anion salts comprising a reactive cation that are useful in variety of organic reactions.
The present invention provides a compound of the formula:
MxQy xe2x80x83xe2x80x83I
where each M is independently a cation, provided at least one M is a reactive cation. Preferably, M is selected from the group consisting of silver cation, aluminum cations, silylium cations, ammonium cations, protonated arenes, and triaryl carbocation. Q is a weakly coordinating anion (i.e., WCA). Preferably, Q is a polyhalogenated polyhedral borate or a fluorinated WCA, and more preferably a polyhalogenated polyhedral borate or a fluorinated polyhedral borate moiety selected from the group consisting of monoheteroborate and aminoborate. Preferably, when Q is a monoheteroborate then M is an aluminum cation. The variable x is an absolute value of the oxidation state of Q, i.e., when the oxidation state of Q is xe2x88x921, then x is 1, and similarly when the oxidation state of Q is xe2x88x922, then x is 2. Preferably, the oxidation state of Q is xe2x88x921 or xe2x88x922. And the variable y is an absolute value of the oxidation state of M. It should be appreciated that when there is more than one type of M is present in the Compound of Formula I, the variable y is the absolute value of the total oxidation states of all M""s present. And similarly, when there is more than one type of Q is present in the Compound of Formula I, the variable x is the absolute value of the total oxidation states of all Q""s present.
Preferably, the aluminum cation is a moiety of the formula (R1R2Al)+1, where each of R1 and R2 is independently selected from the group consisting of alkyl, cycloalkyl, aryl, aralkyl, cycloalkalkyl, alkenyl, and halide. Preferably, each of R1 and R2 is independently selected from the group consisting of alkyl, aryl, and halide. And more preferably, each of R1 and R2 is independently selected from the group consisting of methyl, ethyl, iso-propyl, propyl, butyl, iso-butyl, t-butyl, pentyl, hexyl, and halide.
Preferably, the silylium cation is a moiety of the formula (R3R4R5Si)+1, where each of R3, R4, and R5 is independently selected from the group consisting of hydrogen, alkyl, aryl, aralkyl, cycloalkyl, and halide. More preferably, each of R3, R4, and R5 is independently selected from the group consisting of hydrogen, alkyl, and aryl. And most preferably, each of R3, R4, and R5 is independently selected from the group consisting of alkyl and aryl.
Preferably, the ammonium cation is a moiety of the formula (R16R17R18NH)+1, where each of R16, R17, and R18 is independently selected from the group consisting of hydrogen, alkyl, aryl, aralkyl, cycloalkyl, and silyl. Preferably, each of R16, R17, and R18 is independently selected from the group consisting of alkyl, aryl, aralkyl, and cycloalkyl. More preferably, R16, R17, and R18 are alkyl.
Preferably, the protonated arene is a moiety of the formula (Ar1H)+1, where Ar1 is an optionally substituted aryl. In one embodiment of the present invention, Ar1 is phenyl.
Preferably, the triaryl carbocation is a moiety of the formula (Ar2Ar3Ar4C)+1, where each of Ar2, Ar3, and Ar3 is independently an optionally substituted aryl. In one embodiment of the present invention, Ar2, Ar3, and Ar3 are phenyl (i.e., the triaryl carbocation is trityl cation).
Preferably, the monoheteroborate anion is of the formula ((R6)aZBbHcFdXe(OR7)f)xe2x88x921, where R6 is bonded to Z, Z is bonded to B, and each of H, F, X, and OR7 is bonded to a different boron atom. R6 is selected from the group consisting of polymer, hydrogen, halide, alkyl, silyl, cycloalkyl, alkenyl, alkynyl, and aryl. Preferably, R6 is selected from the group consisting of alkyl, aryl, and sily. More preferably R6 is selected from the group consisting of methyl, ethyl, dodecyl, butyl, iso-butyl, t-butyl, silyl, propyl, iso-propyl, pentyl, hexyl, and a polymer. Z is selected from the group consisting of C, Si, Ge, Sn, Pb, N, P, As, Sb, and Bi. Preferably Z is C. Each X is independently halide. R7 is selected from the group consisting of polymer, hydrogen, alkyl, cycloalkyl, alkenyl, alkynyl, and aryl. The variable xe2x80x9caxe2x80x9d is 0 or, preferably, 1. The variable xe2x80x9cbxe2x80x9d is an integer from 5 to 13, preferably 11. The variable xe2x80x9ccxe2x80x9d is an integer from 0 to 12, preferably cxe2x80x9d is 0. The variable xe2x80x9cdxe2x80x9d is an integer from 2 to 13, preferably 11. The variable xe2x80x9cexe2x80x9d is an integer from 0 to 11, preferably 0. And the variable xe2x80x9cfxe2x80x9d is an integer from 0 to 5, preferably 0. The sum of c+d+e+f is b.
Preferably, the aminoborate anion is a moiety of the formula (R8R9R10NBgHhFi)xe2x88x921, where R8, R9, and R10 are bonded to N, and N is bonded to boron, and each of H and F is bonded to a different boron atom. Each of R8, R9, and R10 is independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, aralkyl, and a polymer. Preferably, R8, R9, and R10 are alkyl. The variable xe2x80x9cgxe2x80x9d is an integer from 6 to 14, preferably 12. The variable xe2x80x9chxe2x80x9d is an integer from 0 to 13, preferably 0. The variable xe2x80x9cixe2x80x9d is an integer from 1 to 14, preferably 11. And the sum of 1+h+i is g.
Preferably, the polyhalogenated borate anion is a moiety of the formula (B12X12)xe2x88x922, where each X is independently halide. Preferably the halide of polyhalogenated borate is selected from the group consisting of Cl and F. In one particular embodiment of the present invention, the polyhalogenated borate comprises at least three fluorine atoms, preferably at least 6 fluorine atoms, more preferably at least 11 fluorine atoms, and most preferably all of the X are fluorine atoms.
One particular embodiment of the present invention provides a compound of the formula:
M1m(R1R2Al)nQq xe2x80x83xe2x80x83IA
where R1, R2, and Q are those defined above; M1 is a non-reactive cation; m is 0 or 1; n is 1 or 2, provided that the sum of m and n is an absolute value of the oxidation state of Q; and q is an absolute value of the total oxidation state of M1 and (R1R2Al), preferably q is 1 or 2, and more preferably q is 1.
Another aspect of the present invention provides a catalyst component comprising the Compound of Formula I.
In one particular embodiment of the present invention, the catalyst component comprises a compound selected from compounds of the formula:
(i) (R1R2Al)((R6)aZBbHcFdXe(OR7)f);
(ii) (R3R4R5Si)((R6)aZBbHcFdXe(OR7)f);
(iii) (R16R17R18NH)((R6)aZBbHcFdXe(OR7)f)
(iv) (Ar1H)((R6)aZBbHcFdXe(OR7)f);
(v) (Ar2Ar3Ar4C)((R6)aZBbHcFdXe(OR7)f); and
(vi) Ag((R6)aZBbHcFdXe(OR7)f),
where Ar1, Ar2, Ar3, Ar4, R1, R2, R3, R4, R5, R6, R7, R16, R17, R18, Z, X, a, b, c, d, e, and f are those defined above.
In another embodiment of the present invention, the catalyst component comprises a compound selected from compounds of the formula:
(i) (R1R2Al)(R8R9R10NBgHhFi);
(ii) (R3R4R5Si)(R8R9R10NBgHhFi);
(iii) (R16R17R18NH)(R8R9R10NBgHhFi)
(iv) (Ar1H)(R8R9R10NBgHhFi);
(v) (Ar2Ar3Ar4C)(R8R9R10NBgHhFi); and
(vi) Ag(R8R9R10NBgHhFi),
where Ar1, Ar2, Ar3, Ar4, R1, R2, R3, R4, R5, R8, R9, R10, R16, R17, R18, g, h, and i are those defined above.
Yet in another embodiment of the present invention, the catalyst component comprises a compound selected from compounds of the formula:
(i) (M1)m(R1R2Al)n(B12X12);
(ii) (M1)m(R3R4R5Si)n(B12X12);
(iii) (M1)m(R16R17R18NH)n(B12X12)
(iv) (M1)m(Ar1H)n(B12X12);
(v) (M1)m(Ar2Ar3Ar4C)n(B12X12); and
(vi) (M1)mAgn(B12X12),
where Ar1, Ar2, Ar3, Ar4, R1, R2, R3, R4, R5, R16, R17, R18, M1, X, m, and n are those defined above.
Still another aspect of the present invention provides a process for preparing an olefin polymer by polymerization of at least one olefin compound in the presence of a catalyst component, where the catalyst component comprises the Compound of Formula I described above. Preferably, the olefin is an xcex1-olefin.
Yet another aspect of the present invention provides an arene-olefin coupling process using the Compound of Formula IA.
Still another aspect of the present invention provides a method for preparing the Compound of Formula I.